Re: Fixed-point LUA_NUMBER

[Enrico Colombini <erix@...>]

Asko Kauppi wrote:
> Depends on your need of maths, since things s.a. sin, cos et.al. will 
> lose their usefulness pretty immediately. I would actually leave such 
> undefined for a fixed-point Lua implementation.

Yes, that's to be expected.

> The C API would be problematic; unless you keep 'lua_Number' as a 
> familiar double and only do the conversion within the core. 

This would be problem #1. Could you be more specific about the 
mechanisms that would break?

> You wouldn't be aware of how addon modules deal with lua_Number, 
> and you wouldn't really even want to know. :)

I wouldn't use any external module... nor many of the standard libs.

> This means you wouldn't just get away with redefining LUA_NUMBER.

Well, it was too good to be true :-)

> If you get it to work, I'd be interested to add fixed point maths into 
> the Numbers patch. And to hear performance comparisons against a hybrid 
> float+int32 approach.

Unfortunately, the fixed-point code is not mine and not public either, 
but should I try this road I'll give some stats. At the moment it's just 
a hypothesis among many.

  Enrico